The invention relates to a fragrance diffusion device, characterized in that it comprises:two opposing walls (30 32 82 84) spaced apart from one another along a longitudinal axis (L) so as to define between them a cavity (C C′) which extends transversely as far as a peripheral wall (40) provided with an opening (42) which places the cavity in communication with the outside of the device,a wick (34 86-92) made of porous material which extends in the cavity along the longitudinal axis passing through the two walls via its two respective opposite ends (34a, 34b) each projecting into an external zone (Z1, Z2) adjacent to the relevant wall,an air intake opening (O1, O2 94a, 94b, 96a, 96b) which passes through each wall in such a way as to place each external zone in communication with the cavity and therefore with the outside of the device.